Recently, as portable electronic devices have come into wide use, they have become necessities of modern life. These portable electronic devices have been developed into multimedia communication devices capable of providing not only an original voice communication service but also various data transmission services and various additional services. Services capable of being provided from the portable electronic device have increased and User Interface (UI) technologies for controlling the portable electronic devices have also been developed continuously.
Recently, as the size of the displays of the portable electronic devices has been competitively increased and resolution thereof has been also enhanced competitively, needs of users for cursive character input, an image memo, etc. have also increased. For example, applications for marking a destination on a map or writing and transmitting a message on a photo have become marketing points. Also, it is necessary to perform cursive character input in a country using Chinese characters like Japan or China. Therefore, with a pen, it is possible to perform an image memo or cursive character input. Accuracy of the image memo or cursive character input can be enhanced.
FIG. 1 illustrates a configuration of an input system using a stylus pen. Referring to FIG. 1, the input system using the stylus pen uses an ElectroMagnetic Resonance (EMR) scheme or an electromagnetic induction scheme and includes a stylus pen 20 and a touch screen device 30. The stylus pen 20 has a tip 21 and includes a resonance circuit therein.
The touch screen device 30 includes a digitizer pad 35, a display panel 34, a window 31, and a digitizer pad controller 36. The digitizer pad 35, the display panel 34, and the window 31 are laminated in order.
The digitizer pad controller 36 supplies alternating current (AC) to the digitizer pad 35. The digitizer pad 35 generates an electromagnetic field. If the stylus pen 20 approaches the electromagnetic field of the digitizer pad 35, an electromagnetic induction phenomenon is generated and the resonance circuit 22 of the stylus pen 20 generates current.
The resonance circuit 22 of the stylus pen 20 forms a magnetic field 23 using the generated current. The digitizer pad controller 36 scans strength of the magnetic field 23 supplied from the stylus pen 20 to the digitizer pad 35 throughout the entire region of the digitizer pad 35 and detects a position. The digitizer pad controller 36 provides the detected position to a host device. The host device performs an operation based on the detected position. For example, the host device can output image information on the display panel 34.
In general, the stylus pen 20 has a resonance circuit 22 which is spaced apart from the tip 21 structurally. When a user holds the stylus pen 20 in his or her hand and touches it on the touch screen device 30, it is slanted. Accordingly, when the stylus pen 20 is slanted, a portion of the stylus pen 20 with a relatively great magnetic field leans toward the touch screen device. Therefore, when the stylus pen 20 is slanted, the digitizer pad controller 36 incorrectly recognizes the position of the tip 21.
FIG. 2 illustrates a touch screen operation using a stylus pen. Referring now to FIGS. 1 and 2, for example, when the user draws a line with the stylus pen 20, the stylus pen 20 which is held in his or her hand is slanted. As described above, the digitizer pad controller 36 incorrectly recognizes the position 42 instead of the position 41 where the tip 21 touches. Because the host device displays a line on the position 42 which is separated from the tip 21 of the stylus pen 20, the user does not have a feeling that he or she uses the stylus pen 20 properly.